adom-step — STEP file viewer

A Fusion 360-style viewer for STEP (.step / .stp) files inside a Hydrogen webview. Renders on the canonical Adom Babylon9 viewer.

What it does

• Components outline — left-sidebar tree of every assembly node in the STEP. Per-row eye-toggle (tri-state across subtrees), isolate, zoom-to, search, right-click context menu.
• Smart-pick measure — Fusion-style snap to vertex / edge / face / body. Two clicks → distance in mm and mils, plus ΔX / ΔY / ΔZ and the angle between picks. Multi-stage Esc to back off one click at a time.
• Hover-inspect HUD — name, breadcrumb path, bbox W×D×H, material swatch, vertex/face count.
• Pin / contact detection — two-mode clusterer that walks the scene graph, groups meshes by inferred material role (body / pin / contact / marker), and surfaces detected pins as individual outline rows. Handles SOIC / QFP / QFN (per-side 1D), LGA / BGA / aQFN (2D bimodal-gap union-find), and through-hole connectors (geometry- based: tall-thin sub-meshes poking below the body's seating plane, regardless of material color).
• Strobe — flash each detected pin once at a configurable interval. Auto-disables with an explanatory tooltip on STEPs where no pins or contacts were found.
• Right-click anywhere in the canvas — Reveal in Components Outline, Isolate, Hide Others, Show, Hide, Zoom To, Copy Name, Properties. All visibility actions are Ctrl+Z / Ctrl+Y undoable; "Hide" auto- flashes the row in the outline so you can find the hidden item again.
• Babylon Inspector — bundled (not CDN), one click opens the full scene-graph debugger.
• CLI mirrors every UI verb — drive the running viewer from the shell or from Claude.

Install

curl -fsSL https://wiki-ufypy5dpx93o.adom.cloud/static/apps/adom-step/adom-step -o /tmp/adom-step \
  && chmod +x /tmp/adom-step \
  && sudo install -m 0755 /tmp/adom-step /usr/local/bin/adom-step \
  && adom-step install

adom-step install deploys SKILL.md + completions to ~/.claude/skills/ and ~/.local/.

Quick start

# Open any STEP file:
adom-step view /path/to/design.step

# Open a KiCad library footprint by canonical name:
adom-step view-library Package_QFP/LQFP-64_10x10mm_P0.5mm

# Drive from the CLI / from Claude:
adom-step list-components               # tree dump
adom-step isolate U1                    # hide others + frame
adom-step show NAME / hide NAME / show-all
adom-step measure A B                   # mm + mils
adom-step pins list                     # detected clusters
adom-step pins isolate 3
adom-step pins strobe                   # flash each pin
adom-step view-cube iso                 # front | top | iso | home | ...
adom-step screenshot --out /tmp/x.png
adom-step eval "return Object.keys(window.adomStep)"
adom-step console -f                    # tail webview console

Pipeline

.step  →  service-step2glb /convert  →  GLB (hierarchy + materials preserved)
       →  /tmp/adom-step-cache/<sha256>.glb
       →  Babylon SceneLoader.ImportMeshAsync
       →  scene.transformNodes  →  components outline

The conversion side uses OCCT XCAF + RWGltf_CafWriter, which preserves the STEP product structure and per-face materials end-to-end. That's why TI / Renesas / Nordic STEPs surface their named pin hierarchy directly (no client-side STEP parsing).

See also

• service-step2glb — the OCCT-based converter that produces the GLBs.
• adom-3d-viewer-babylon9 — the canonical Babylon9 viewer adom-step renders into.
• chip-fetcher — source of the manufacturer STEPs adom-step is tuned for.